Ammunition magazines are well known in the art of firearms. Their basic construction is a containment shell with two open ends. One end is deemed the “floor” of the magazine and is covered by a plate while the opposite end is the “feed” end and interfaces with the weapon. Inside the volume defined by the shell and plate is a spring and follower assembly. When ammunition is loaded into the magazine, the ammunition pushes the follower down towards the floor and thereby compresses the spring. In use, when one magazine is expended, the compressed spring releases and pushes the follower and associated ammunition upwards toward the feed end and the next round of ammunition is thereby readied.
Prior magazines have been manufactured in many different configurations and of different materials. Perhaps the best known in the U.S. are the AK-47 and the USGI AR15/M16 magazines. These magazines function similarly, though they are made with slight variations to interface with their host system. Of notable difference is that the AK-47 magazine has a relatively constant curvature while the AR15/M16 magazine has a less curved lower region that gradually resolves to a more linear function towards the feed end. Both use the same type of internal system. Of particular note with both, and all follower magazine systems, is that the system works well only as the follower smoothly travels the inside of the magazine. This is to say that the follower evenly distributes pressure on the round stack, even as other factors of the magazine and stack, including magazine curvature, case taper and upward pitch of the follower, are all considered and addressed. As the follower must move, there is room for the follower in all the known prior art magazines to move axially, or “wobble” and possibly jam. This is notorious in the AR15/M16 magazine style as the geometry of the magazine is inherently not uniform. The parent application involves a solution to these issues for a larger capacity magazine (30 rounds) by presenting a magazine with a constant internal curve and a follower with severely limited motion. However, these solutions are not well received with a smaller (20 round) capacity magazine, as curved 20 round magazines tend not to fit certain weapons. Consumers also tend to prefer their smaller capacity magazines straight and straight magazines are easier to mold.
The present invention is a polymer magazine with an angularly shaped guide rails to interface with the internal follower, thereby restricting, but not totally inhibiting axial motion of the follower. The magazine also features a two-piece floor plate locking system. The present invention represents a departure from the prior art in that the magazine of the present invention allows for more controlled and level motion of the follower while the magazine is loaded or unloaded.